Thomas H. Kunz

Abstract

Previous article FreeIn MemoriamThomas H. KunzChristopher S. Richardson, Wendy Hood, Louise Allen, Nick Hristov, Katherine Ineson, Jonathan Reichard, Gary McCracken, Allen Kurta, and D. Scott ReynoldsChristopher S. Richardson1Department of Natural Sciences and Mathematics, Lesley University, 29 Everett Street, Cambridge, Massachusetts 02138*Corresponding author; email: [email protected]. Search for more articles by this author , Wendy Hood2Department of Biological Sciences, Auburn University, 101 Rouse Life Sciences, Auburn, Alabama 36849 Search for more articles by this author , Louise Allen3Institute for Learning and Teaching, Colorado State University, 801 Oval Drive, Fort Collins, Colorado 80521 Search for more articles by this author , Nick Hristov4TERC, 2067 Massachusetts Avenue, Cambridge, Massachusetts 02140 Search for more articles by this author , Katherine Ineson5Department of Natural Resources and the Environment, University of New Hampshire, James Hall, Room 114, 56 College Road, Durham, New Hampshire 03824 Search for more articles by this author , Jonathan Reichard6US Fish and Wildlife Service, 1849 C Street NW, Washington, DC 20240 Search for more articles by this author , Gary McCracken7Department of Ecology and Evolutionary Biology, University of Tennessee, Dabney Hall, 1416 Circle Drive, Knoxville, Tennessee 37996 Search for more articles by this author , Allen Kurta8Department of Biology, Eastern Michigan University, 441 Mark Jefferson, Ypsilanti, Michigan 49197 Search for more articles by this author , and D. Scott Reynolds9Department of Science, St. Paul’s School, 325 Pleasant Street, Concord, New Hampshire 03301 Search for more articles by this author Full TextPDF Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinked InRedditEmailQR Code SectionsMoreCareers in biology are often motivated by a love for wildlife and the outdoors, and a fascination with the processes and mechanisms that gave rise to life, its diversity, and the patterns that emerge within its complexity. Yet during the unprecedented times of the COVID-19 pandemic, with its lockdowns and isolation, many of us have taken the time to reflect and realize that the most meaningful aspects of our careers are the connections we make through our science and the positive impact that we can have on others. Thomas Kunz was an admirable example of a biologist who not only made substantial contributions to science and bat conservation but also positively affected the lives of students he mentored and the collaborators with whom he worked. On the one-year anniversary of his death, we reflect on Tom’s impact and pay tribute to his personal and scientific legacy. First, we briefly summarize the major highlights of Tom’s life and career. Then, we reflect on the diverse ways Tom has impacted our lives both personally and scientifically.Thomas Henry Kunz was born on June 11, 1938, in Independence, Missouri, and died on April 14, 2020, in Dedham, Massachusetts, from complications of COVID-19. Tom was a first-generation college graduate who went on to a 40+-year career as a highly respected, honored, and beloved professor of biology at Boston University. Details of Tom’s early life, his personal attributes, and his professional accomplishments can be found in other obituaries prepared shortly after his death (Fenton and Swartz 2020; Kurta et al. 2020; McCracken 2020).Tom received his BS degree in biology in 1961 from Central Missouri State University, where he played varsity football and cocaptained the football team. He then coached football at the same school while earning a master’s degree in education in 1962. Following four years as a high school biology teacher and football coach, Tom received an MS in biology from Drake University in 1968. In 1971, he earned his PhD in the Department of Systematics and Ecology at the University of Kansas.That same year, Tom accepted a faculty position in the Department of Biology at Boston University, where he remained for his entire career. During Tom’s four decades at BU, he mentored 20 postdoctoral associates, 31 PhD scholars, 16 MS students, and hundreds of undergraduates. He authored approximately 360 research papers and edited seven books. Tom performed significant service to the university as chair of the biology department (1985–1990), cofounder and director of the Tiputini Biodiversity Station in Ecuador, and founder and director of Boston University’s Center for Ecology and Conservation Biology. He was elected a fellow of the American Association for the Advancement of Science (1990). He became an honorary lifetime member of the American Society of Mammalogists, and later he was elected its president (2000–2002). He received a Lifetime Achievement Award from the Karst Waters Institute (2008), the Gerrit S. Miller Award for outstanding service and research to bat biology (1984), and the C. Hart Merriam Award for outstanding contributions to mammalogy (1998). In 2011, he was named William Warren Fairfield Distinguished Professor, Boston University’s highest faculty honor.By any standard, Tom Kunz’s life was enormously successful. At the time of his death, Tom resided at NewBridge on the Charles nursing facility, where he lived with injuries from a pedestrian-automobile accident in October 2011. Tom is survived by his wife of 58 years, Margaret; daughter, Pamela; son, David; and five grandchildren. He also leaves behind hundreds of grateful friends, colleagues, and students from around the world.We pay tribute to Tom and his impact in three important areas: his contribution to the field of physiological ecology, his cross-disciplinary and interdisciplinary impact on science, and his mentorship of undergraduate and graduate students. Tom’s legacy is particularly reflected in the collective spirit of connection and collaboration that he encouraged. We draw primarily from the recollections of his graduate and undergraduate mentees and highlight the ongoing impact of Tom’s work.Contribution to Physiological EcologyOne of the experiences that had the greatest impact on Tom’s choice of research directions was a field course in advanced ecology that he took at the University of Nebraska, Lincoln, while on summer break from teaching high school. The course was taught by Thomas B. Thornton, who studied how bull sharks (Carcharhinus leucas), a marine species, survive in the freshwater of Nicaraguan lakes. It was Dr. Thornton who first encouraged Tom to consider the importance of physiology when trying to interpret an animal’s ecology.With Dr. Thornton’s advice in mind, Tom crafted his dissertation on bats exploring how differing environments and colony sizes affected roosting ecology, reproductive phenology, and postnatal growth in the cave myotis (Myotis velifer; Kunz 1973). He was particularly intrigued by his discovery that the bats affected the ambient temperature and humidity of their own roost. Tom surmised that this behavior would greatly impact an animal’s daily energy budget.After finishing his PhD and accepting the position at Boston University, Tom, as well as his students, continued to explore the interface between ecology and physiology in his favorite subjects, bats. As described by former Kunz PhD student Jay Storz, “Many physiologists have achieved success by focusing on particular questions about how organisms work and then—by applying the Krogh principle—they identify a particular study animal that is especially well suited to investigating the phenomenon of interest. Tom achieved great success by inverting that principle. He focused on a specific group of animals and allowed discoveries about their biology and natural history to guide research into more general questions about ecological physiology.” Using bats as a model, Tom and his students addressed questions about energy use and life-history trade-offs, reproductive and parental effort, immune responses to disease, effects of stress on animal physiology, and more.Tom worked with his students to expand and deepen the understanding of the interplay between physiology and ecology. He encouraged his students to build on emerging biological concepts and use new technology in novel ways to do research that had applications beyond the biology of bats. He also supported graduate students who worked in other fields, such as behavioral ecology, genetics, and community ecology. Throughout this process, Tom also was a friend and a father figure to many of his students and colleagues.In the 1970s and 1980s, much of the emphasis of the “Bat Lab” in Boston was on quantifying the energetic and nutritive requirements of pregnancy, lactation, and growth of bats (Burnett and Kunz 1982; Kunz et al. 1983; Kurta et al. 1987, 1989a, 1990) and how bats altered their foraging patterns, dietary choices, and roosting behavior in response to changing metabolic demands (Anthony et al. 1981; Kunz and Anthony 1982, 1996; Kurta and Kunz 1988). These projects included the work of graduate students Edythe Anthony, Chris Burnett, Holly Stack, and Allen Kurta. The subjects of these early studies were the big brown bat (Eptesicus fuscus) and little brown myotis (Myotis lucifugus), which gathered in maternity colonies inside barns and attics in the area surrounding Boston (fig. 1).Figure 1. Little brown bat (Myotis lucifugus) maternity colony in Milford, New Hampshire. Tom Kunz, and his graduate and undergraduate students, performed physiological and ecological studies of these bats at this site since the 1990s. Two coauthors continue to study bats in this colony. Photograph taken by Katherine Ineson in 2018.View Large ImageDownload PowerPointMost physiological studies up to that time focused on animals maintained in the artificial conditions of the lab for prolonged periods. Tom realized that these variables evolved in a natural context and, thus, ecologically relevant data must be collected under conditions that were as natural as possible. Consequently, studies of milk composition were based on samples obtained from mothers plucked from their roost (Kunz et al. 1995; Stern et al. 1997), growth of juveniles was quantified based on the mark and recapture of known-aged wild animals (Kunz and Robson 1995; Hoying and Kunz 1998; Hood et al. 2002), and oxygen consumption measurements were measured in bats clustered inside a simulated roost (a wooden beam) placed within a local attic (Stack 1985), which allowed the temperature to fluctuate with that of the natural roost.While these were not controlled laboratory studies, Tom encouraged scientific rigor and consistency in how field studies were performed. Tom brought Christopher Richardson into his lab with the goal of expanding the understanding of how bats use energy within the boundaries of physiological plasticity, which ultimately was shaped by evolutionary processes. Chris’s PhD research focused on how temporal and microgeographic variation in hormones affected intraspecific variation of basal metabolic rate (BMR) in bats, shedding light on the physiological plasticity of bats (Richardson et al. 2009, 2018). Chris observed that external factors (e.g., microhabitat differences such as roost type) had a large influence on intraspecific variation in BMR and in the plasma concentrations of metabolic hormones such as thyroid hormone and leptin.Tom was a master at integrating information from an array of techniques, such as body composition analyses, metabolic measurements, behavioral time budgets, and recordings of environmental parameters (Anthony et al. 1981; Reynolds et al. 2009; Richardson et al. 2009). He pushed the envelope of using new tools to address more cutting-edge questions. Tom often challenged his students to incorporate laboratory methodology into their field research, leading to his editorship of seminal books on field and laboratory methods in the study of bats (Kunz 1988; Kunz and Parson 2009) and to his lab publishing many of the early uses of physiological techniques in the field, including total body electrical conductivity analysis, thermocouple data logging, and thermal imaging (Kunz et al. 2008; Betke et al. 2008; Reynolds et al. 2009; Hristov et al. 2010). He forged collaborations that introduced his research team to technologies and techniques that collectively increased the breadth of their research.In the early 1980s, Tom and his laboratory group began collaborating with Kenneth Nagy of UCLA, to determine field metabolic rates of bats from the temperate-zone family Vespertilionidae using doubly labeled water (DLW; Kurta et al. 1989a, 1989b, 1990). Later, Tom expanded the application of DLW to bats of other feeding guilds. After receiving a call for collaboration from Otto von Helversen and York Winter from the University of Erlangen, Tom investigated the energetics of Neotropical nectar-feeding bats with the University of Erlangen group (Norberg et al. 1993). Tom developed a long-term collaboration with Christian Voigt based on their investigation of the physiological ecology of nectar-feeding bats using both the DLW (Voigt et al. 2003a) and stable isotope (Voigt et al. 2003b) techniques. Using DLW, Tom and Christian looked at the energetic costs of harem maintenance in Saccopteryx bilineata (Voigt et al. 2001). Later, they examined the nutritional and physiological constraints of fruit-eating bats in the Amazonian rainforest (Voigt et al. 2008). Tom’s collaborative work on using DLW in bats advanced the study of energetics in mammals, including the study of field metabolic rates.The wealth of information that Tom and his lab had accumulated on the ecology, behavior, and physiology of M. lucifugus and E. fuscus resulted in some of the most holistic sets of studies on any bat species. Among these was the twenty-ninth-most-cited paper in the history of PBZ (Garland et al. 2017), which was on the energetics of reproduction in M. lucifugus (Kurta et al 1989a). However, despite his focus on bats, Tom’s work was never about just one taxon. He was fascinated by what bats could tell us about mammals and life on earth, in general.In the 1990s, Tom’s focus on integrating field and laboratory methods expanded with Scott Reynolds’s PhD focusing on life-history trade-offs and body composition analysis as a demographic trait (fig. 2). With Tom’s guidance and support, Scott’s long-term research on M. lucifugus showed the influence of body composition (lean and fat mass) on primary demographic variables, such as reproductive timing, postnatal growth rate, and juvenile recruitment (Reynolds and Kunz 2000). Scott’s focus on individual variation in these traits, rather than just the population mean, was the direct result of Tom’s insight into the functional value of physiology in life-history dynamics of natural populations. He encouraged the study of phenotypic variation (see Bennett 1987) in both physiological and ecological studies of animals.Figure 2. Bat house (aka bat hotel) in maternity colony in Princeton, Massachusetts. This is one of the first bat colony–size structures to go into a preexisting space, such as an attic or a barn. It was installed by the colony owner at Tom Kunz’s request in the mid-1990s. Photograph taken by Michael Singh in March 2021.View Large ImageDownload PowerPointTom brought Wendy Hood into the lab to further his work on milk and the life histories of bats. He introduced Wendy to lactation expert Olav Oftedal. With training on bats and energetics from Tom and guidance on mammalian lactation and nutrition from Oftedal, Wendy tackled the question, “Does low calcium intake constrain the reproductive patterns of bats?” Her research on E. fuscus partially refuted this idea. Low calcium availability is unlikely to be responsible for the slow pace of life observed in the Chiroptera, because bats are not different from other mammals in the loss of bone calcium or in the production of milk calcium during lactation (Kunz and Hood 2000; Hood et al. 2006).Tom cared deeply for the animals he studied (fig. 3). When bats began dying of a mysterious condition in New York, Tom took a multifaceted approach to understanding the likely causes. Tom received a call from Al Hicks (who was leading the investigation into many dead bats in caves and mines in New York). Tom brought his knowledge of energetics of hibernation and torpor patterns, as well as experience with relevant technology, to help with the investigation. Tom and his graduate students Jon Reichard and Marianne Moore brought their expertise and equipment to the scene in an effort to understand torpor patterns of sick bats and collect tissues that could be used to investigate what was just beginning to be known as white-nose syndrome (WNS).Figure 3. Tom Kunz using night vision goggles to count bats as they emerge from a Myotis lucifugus maternity colony in Paxton, Massachusetts, in 2010. It is one of the largest surviving post–white-nose syndrome colonies left in the state. Photograph taken by Katherine Ineson.View Large ImageDownload PowerPointMarianne and Jon combined approaches to investigate relationships between energetics, torpor, and immune function in diseased and control bats. Jon used handheld cameras to assess body temperatures and time-lapse thermal imagery to track arousal behavior and associated these observations with measurements of body condition that linked torpor patterns to fat storage. Then he continued to monitor bats after they emerged from hibernation to assess their condition through spring and into the reproductive season. Marianne measured immune function in bats with and without WNS to help understand how bats respond to infection (Moore et al. 2011, 2013). Kate Langwig (graduate student) investigated factors that affected the impact of WNS in different bat species (Langwig et al. 2012). Later, the importance of studying how bats recover from WNS during the posthibernation period involved Chris Richardson (a postdoctoral fellow at that time), who focused on the link between energy use and immune function in bats with WNS (Richardson et al. 2020; fig. 4), and Nate Fuller (graduate student), who focused on the histology of the disease (Fuller et al. 2020).Figure 4. A, Chris Richardson (Tom Kunz’s former PhD student and former postdoctoral fellow) and Caitlin Looney collecting a blood sample from a little brown bat (Myotis lucifugus). B, Chris and Caitlin collecting a blood sample from its interfemoral vein. C, Chris processing blood samples taken from multiple M. lucifugus. The bats were captured at the bat maternity colony in Lincoln, Massachusetts, in 2018. This colony has been studied since the 1990s. Chris and Katherine Ineson continue to study the colony as part of a study of the intrinsic factors that affect the population recovery of M. lucifugus from white-nose syndrome. Photographs taken by Katherine Ineson (A, B) and Caitlin Looney (C).View Large ImageDownload PowerPointTom and his students helped set the scientific stage for understanding the complex physiological processes that play a role in WNS, which is now impacting bats in much of North America. Using the tools that they developed under Tom’s mentorship for other physiological ecology questions and a well-rounded and adaptable skill set, Tom’s former students, as well as their teacher, were prepared to respond to whatever research or conservation need came their way. In the case of WNS, Tom helped lay the groundwork for rapid scientific progress to address this emerging wildlife crisis, which some of his former students and collaborators continue to advance today.Interdisciplinary Collaborations, Technology, and Public Dissemination of ScienceWhen Nick Hristov joined Tom’s group as a postdoctoral fellow in summer 2004, Tom had already been working for several years with NEXRAD Doppler radar to track emerging colonies of bats at the landscape level in south-central Texas, the summer home of the world-famous colonies of Brazilian free-tailed bats (Tadarida brasilenis). He had also recently begun working with thermal imaging and computer vision to study the same colonies on the ground.For Jeff Frank, then vice president of development at Indigo Systems, the leading manufacturer of thermal technology in the world, the revelation about the biological potential of thermal imaging happened when he was watching National Geographic struggle to film the undisturbed behavior of African lions at night. For Jeff, the real potential of the technology in biology, however, was not realized until he met Tom, based on National Geographic’s recommendation, to study the biology of bats. Following expeditions to Costa Rica and Belize, and three National Geographic specials later, the two formed a lasting collaboration and friendship shaped by their fascination with technology and nature. Their partnership expanded further when they started working together in the Hill Country of Texas, investigating the ecological and economical importance of T. brasilenis in the south-central US.Beyond monitoring bat behavior at night, the thermal cameras were uniquely suited for detecting and tracking the numerous bats in flight (fig. 5). This technology allowed Tom and Jeff to answer a seemingly simple but incredibly challenging question: “How many bats live in large roosts, such as Bracken Cave (Kunz and Parsons 2009)?” While early prototypes were tested at one cave, Tom’s collaboration with the computer vision group of Margrit Betke at Boston University brought advancements in software development that pushed the capabilities further and allowed population monitoring at dozens of sites (Hristov et al. 2008; Ammerman et al. 2009; Hallam et al. 2009).Figure 5. Bats flying in the evening in Blanco County, Texas, in 2007. Photograph taken by Nick Hristov using a thermal camera.View Large ImageDownload PowerPointCombining similar advancements in Doppler radar, thermal imaging, remote sensing, computer vision, and acoustic monitoring with DNA analysis and mathematical modeling, Tom, working with long-time collaborator Gary McCracken, assembled an interdisciplinary team that was awarded a National Science Foundation (NSF)–Integrated Technology Research (ITR) grant, one of very few successful proposals of this scope for an ecological and field research group. This award supported an interdisciplinary collaboration spanning more than 10 years, over $4.2 million in funding, and dozens of publications ranging in scope from methods for computer vision analysis to population dynamics and agroecoservices (Cleveland et al. 2006; Theriault et al. 2010).With Tom’s leadership, the interdisciplinary team rewrote the basic understanding of T. brasilenis bat colony sizes to show that historic counts were vastly overestimated and brought to the surface never-before-seen imagery of bats and their behavior from the depths of the karst caves (Betke et al. 2008; Hristov et al. 2010). Tom’s interdisciplinary collaboration was also instrumental in advancing research on the ecosystem services provided by bats (Kunz et al. 2011), a concept that has since become a stronghold in the bat conservation movement. He recognized the importance of estimating the economic value of the often-hidden pest suppression, seed dispersal, and pollination services provided to humans by bat species worldwide (Kunz et al. 2011). A more explicit valuing of these services helped improve public perceptions of bats as well as improved advocacy for the protection of bat populations and their associated habitats.Later, the cameras were outfitted with a one-of-a-kind thermal telephoto lens (on loan from FLIR) to study the migratory behavior of birds and bats at night in New England (a collaboration with Ron Larkin and Louise Allen). Thermographic work investigated the energetics of flying bats and thermal regulation of entire roosting colonies (a collaboration with Jon Reichard; Reichard et al. 2010a, 2010b), which led to using tumor-imaging technology to characterize a unique organ for heat balance in bats (a collaboration with the University of Texas Health Science Center; Reichard et al. 2012). Tom and his collaborators and students constructed 3D models of caves complemented by emerging LiDAR (light detection and ranging) scanners to study underground bat navigation and group behavior (Hristov et al. 2013). They applied these tools to understand emerging threats to bats such as interactions with wind turbines and the thermal characteristics of hibernating bats as WNS spread across North America (a collaboration with Bat Conservation International, Jason Horn, Ed Arnett, and coauthors; Kunz et al. 2007a,2007b; Horn et al. 2008). They continued to innovate, further expanding the use of ground-based radar and designing the first multicamera field system for 3D reconstruction of bat flight using thermal imaging (a collaboration with Margrit Betke and Sharon Swartz; Wu et al. 2009; Theriault et al. 2010). Airplane-based telemetry was used to track and record bats flying in the open airspace at unprecedented speeds (a collaboration with Martin Wikelski; McCracken et al. 2016).In all of this, Tom always had the time, attention, energy, and passion to share the excitement of discovery with his coworkers. In Tom’s groups and projects, there was always time for unstructured play, to try things out, repurpose, and push the limits further. Innovation emerged from these interactions while building interdisciplinary collaborations that moved entire fields of science forward. In 2008, this led to an opportunity to organize a symposium at the Society of Integrative and Comparative Biology annual meeting representing this body of work. In early discussions, Tom’s collaborators suggested “bats” as the theme of the symposium. However, Tom had been thinking about a symposium much bigger in scope with a greater interdisciplinary vision. The symposium was on aeroecology, one of the culminating accomplishments of Tom’s scientific career. Aeroecology was an emerging discipline that highlighted biological interactions in the aerosphere and the prominent place of technology in the advancement of this new scientific enterprise (Kunz et al. 2008). The aerosphere is the planetary boundary layer of the Earth’s atmosphere that supports the many different airborne organisms that, to a large extent, depend on this fluid environment for their existence (Kunz et al. 2008).Tom connected with technology not only through what it could do for science but also for what it could do for public understanding of science. Tom and many of his students and colleagues took a pithy approach to translating fascinating science for a broader public audience. Using still images and video, they crafted visual narratives that electrified the otherwise restrained character of the typical scientific publication and went beyond the sharp-styled pens of science journalists. Near the end of Tom’s career, Tom, with his students and collaborators, was giving presentations and research talks to thousands of national park visitors and over a dozen research societies. Tom often engaged in many informal talks and demonstrations for people keen to see what he was working on. In these interactions, the foundations were laid for what would become iSWOOP, a large-scale NSF-funded initiative for making science in national parks visible to their millions of annual visitors (Merson et al. 2016; Hristov et al. 2018). Tom knew that helping the general public understand the facts about bats, wildlife, and the environment is especially important for promoting effective, meaningful government policy to support a broader scientific research agenda.Impact on Others, Particularly through Mentorship of His Undergraduate and Graduate StudentsOver 60 postdoctoral fellows, PhD scholars, and master’s-level students and hundreds of undergraduates had the honor of working with Tom during his long career. An academic family tree (fig. 6), which includes every PhD student and their students (at the PhD level), highlights his academic legacy. Additional students of Tom’s, including master’s and postdoctoral scholars, are included in the appendix. Tom regularly asked his graduate students to recite their academic lineage during their oral PhD candidacy exams. Many of his graduate students learned and relayed back this history before it was readily available on a single webpage (http://www.academictree.org). Their predecessors could be traced to Joseph Grinnell, the first director of the Museum for Vertebrate Zoology at the University of California, Berkeley. Grinnell was a staunch field biologist, and many consider him a founder of mammalogy (and ornithology) in the United States. Now that an academic tree can easily be traced online, a critical transition is revealed in Tom’s lab and the labs of many others of his generation. Tom’s antecedents were almost entirely white men. Indeed, Tom’s PhD graduate advisor, J. Knox Jones Jr., graduated 18 PhD students, and only one of these students was a woman. Despite his history of being trained in a male-dominated field, Tom supported the careers of many women. Eighteen of the 30 students who completed their PhD in Tom’s lab were women. Tom also advised eight international students, many of whom took lessons learned from working with Tom back to their home countries, further broadening Tom’s influence.Figure 6. Tom Kunz’s academic lineage, including all students completing PhDs in his lab and all of the PhD descendants. Those PhD students whose work is in progress are noted by an asterisk.View Large ImageDownload PowerPointTom was especially committed to broader impacts, including